The disclosure generally relates to a communication system and, more particularly, to a communication system with radio interworking capability and related user equipment.
A base station of a mobile communication network is only capable of communicating with a certain number of user equipments within a certain wireless transmission range. Therefore, many technologies have been developed to increase the amount of user equipments that can be served in a certain area, to balance the load in the mobile communication network, to improve the communication quality, etc. For example, the traditional mobile communication network may adopt a radio interworking mechanism to provide both the 3GPP radio access resources and the wireless local area network (abbreviated as WLAN) radio access resources at the same time so as to improve the system performance.
Traditional core network based WLAN interworking mechanisms, such as ANDSF (Access Network Discovery and Selection Function), have defined an access network selection method for instructing the user equipment to select an available WLAN according to predetermined intersystem mobility information. Different access network selection method in the RAN (Radio Access Network) level is being currently developed in order to further improve the WLAN/3GPP interworking performance.
Accordingly, ANDSF based access network selection method and different RAN based access network selection method may be applied to the user equipment at the same time in the future. Without proper integration of the access network selection methods defined in different levels, the user equipment may not able to fulfill the intersystem mobility policy configured by the mobile communication network operator.